dang FBI
Not really BP related response,............. but there was a point in time where a lot of federal LE agencies, and I suspect state and local agencies following the federal lead, switched from the old standby OO buck, to #4B, and it wouldn't surprise me that the FBI "determined" same in that era. I've got a vintage article from the 'Nam era that appeared in the "Rifleman" where #4B was suggested for military use due to the higher hit probability. The #4B load was the standard buckshot load for the NPS at the front of my career in the early to mid 80's, and a lot of it was shot at the Federal Academy (FLETC) by outfits like the Border Patrol, Bureau of Prisons, and so forth.
When they got around to shooting felons with #4B, the results were not so hot. I clearly recall an officer survival lecture from a Border Patrol agent who dusted an assailant with a least two loads of #4Bh and the guy escaped back into Mexico, who knows if he survived or not, the agent took a couple of M1 carbine rounds and did survive. When the NPS finally shot a felon with #4B , the suspect went down but was still animated, later to expire in the ER. By the early '90's, most agencies of my acquaintance were back to OO buck.
I knew deer dog hunters who shot #4B, the accepted target was to sieve the deer's head and neck. I've skinned one whitetail that had a number of #4 buck buried up in the muscles and against the shoulder blade and ribs. I still have a box or two of #4B, and have experimented with it as a coyote load through my 870 and assorted choke tubes and have never been impressed out past 30 yds or so.
